In the Egyptian city of Alexandria, a crowd of Muslim demonstrators tries to storm a Coptic church to protest at a play about a Muslim campaign to convert Christians.

In Iraq, the Christian middle class is emigrating in droves, fearful of the daily violence and the hostility it now encounters from Islamists.

In Saudi Arabia, churches and other places of non-Muslim worship are banned, and foreign workers who try to hold secret Christian services are jailed, flogged and often deported.

In the land of its birth, Christianity is in sad decline as the pressures of life under Israeli occupation and the growth of militant Islam push Palestinian Christians from Jerusalem and the West Bank.

Being anti-Christian is a way of showing what a good Muslim you are

Lebanese journalist Hazem Saghie

Few issues are so sensitive as the position of Christians in the Middle East.

Some Christian Arabs seek to minimise the difficulties they face, either to avoid trouble or to present themselves in a patriotic light.

At the other extreme, some outsiders - for example, in the United States - exaggerate the plight of Middle East Christians, depicting them as wholly marginalised and on the verge of extinction.

A varied picture

There is no agreed figure for the number of Christians in the region.

Robert Betts, an American expert on the subject, reckons there are at most 10 million.

The largest number are in Egypt (perhaps six million). Lebanon and Syria each have over a million, with smaller communities in Iraq, Jordan, Israel, the Palestinian territories, Turkey and Iran.

There are also several million Christians in southern Sudan (though not strictly part of the Middle East).

Under pressure

Middle East Christians have deep roots. And, for the most part, Muslims and Christians have long lived in peaceful coexistence.

But a number of factors are stirring up tension.

Only half a million Christians are thought to remain in Iraq

In Iraq, the rise of both Sunni and Shia Islamism, especially since the US-led invasion in 2003 and the overthrow of Saddam Hussein, has helped generate a new climate of sectarianism.

Well-to-do Christians are among those who have been targeted for robberies and kidnappings.

In both Sunni and Shia areas, Christian women are forced to cover their heads.

Scores of doctors and other professionals have fled abroad.

One Iraqi Christian businessman told the BBC: "Christians started to leave in Saddam's time because of the oppression. Now they are leaving for a new reason - fear of religious persecution."

He estimates there are only half a million Christian Iraqis left in the country.

Holy Land blues

Throughout the region, secularism is in retreat and religious politics on the rise.

In the current climate, says the Lebanese journalist Hazem Saghieh, "being anti-Christian is a way of showing what a good Muslim you are".

"Egypt is the exception where there is constant tension - resentment by the Copts at being excluded from any position of power and resentment by Muslims of the Copts' clannishness and generally higher standard of living."

Tensions are constant feature of life in Egypt, say experts

In Jerusalem and the West Bank, Christian and Muslim Arabs have lived side by side for centuries.

Christians were always active in the Palestinian national movement and today one of the best-known Palestinian voices is that of Hanan Ashrawi, a Christian academic and human-rights activist.

But the rigours of life under Israeli occupation - and the rise of the militant Islamic groups Hamas and Islamic Jihad - have made many Palestinian Christians fearful.

Those with the means to do so have packed their bags and left for Europe or North America or elsewhere.

Once 15% of the Palestinian population in Israel and the West Bank, today Christians make up only 4%.

Evangelical zeal

For Middle East Christians, the role of outsiders is sometimes problematic.

"The 'old churches' which work in Jerusalem and the West Bank (Orthodox, Catholic, Lutheran and Anglican) have a Palestinian flock and so tend to be pro-Palestinian," says Victoria Clark, author of Holy Fire, a book about the role of Western Christendom in the Holy Land.

In contrast, she says, the American evangelical churches, relative newcomers on the scene, are ardent supporters of Israel and Israel's retention of the occupied territories.

Though they have made few converts in the Middle East, the evangelical churches are an influential part of President Bush's political constituency in the United States.

In the current climate in the region, no-one wants to be tarred with the American brush.

"I am a nationalistic Iraqi," declares one doctor proudly. "But since the US-led invasion, other Iraqis call me a stooge because I'm a Christian."